Open AccessInfluence of individual roughnesses nozzle edge on the length of the supersonic section of an underexpanded microjet
Author(s) -
С. Г. Миронов,
В. М. Анискин
Publication year - 2019
Publication title -
journal of physics. conference series
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.21
H-Index - 85
eISSN - 1742-6596
pISSN - 1742-6588
DOI - 10.1088/1742-6596/1404/1/012087
Subject(s) - nozzle , pitot tube , materials science , mechanics , supersonic speed , enhanced data rates for gsm evolution , leading edge , outflow , geometry , optics , composite material , flow (mathematics) , physics , engineering , mathematics , thermodynamics , meteorology , telecommunications
The paper presents the results of the experimental investigation of the influence of a small group of roughnesses uniformly located on the edge of the convergent nozzle on the length of the supersonic core of an underexpanded air microjet. The tests are carried out on the low-pressure test bench with the aid of the Pitot tube. The set of nozzles with the diameter of 2 mm, with the smooth output edge and the edge of the similar shape roughnesses (from 2 to 4) is used. The underexpanded microjets flowing out from the nozzles of the diameter 10.6; 16.1; 21.4, and 34.8 μm are simulated by the outflow Reynolds number. It is shown that the presence of roughnesses can reduce essentially the supersonic section length and eliminate the previously found effect of microjet “relaminarization”, however the reduction value dubiously depends on the amount of the roughnesses on the nozzle edge.